Apparatus for mixing air and gas



jan., 29" 1924. 1,482,011

' T. L.. HlLEs APPARATUS Fon MIXING AIR Aun ens original Filed May 51 1919 5 sheets-shun Jan., 29 1924.

T. L. lI-HLES APPARATUS FOR MIXING AIR AND GAS Original Filed May 31 1919 5 Sheets-Sham 2 A TTORA'E Y .Ham 29 1924, AZQM T. L. HILES APPARATUS FOR MIXING AIR AND GAS .Original FiledMay 31 1919 5 Sheets-Sheet 3 J WTNESSES.- [AVENTOR @m m, www@ jan, 29 -1924., 3,482,01l

T. L. HILES APPARATUS FOR MlxING AIR AND GAS Original Filed May 31 1919 5 Sheets-Sheet 4 WTNESSES.- yINVENTOR M .A QQ-M?? APPARATUS FOR MIXING AIR AND GAS Original Filed May 31 P 1919 5 Sheets-Sheet 5 WITNESSES: IA'VENTOR EY f f TTOK'EYJ ranma-.a aan. 2e, 1924.

Nrran STATES.

'ramon I.. nILEs, or NrLEs, nimma.

APPARATUS FOR MIXING AIB .AND GAS.

Application `filed May 31, 1919, Serial No. 301,112. Renewed Hay S1, 1923.

To all 107mm z'tmay concern:

Be it known that l, THnnoN citizen of the United States, .residin at Niles, in the county of Berrien and tate of Michigan, have invented certain new and useful Improvements in Apparatus for Mixing Air and Gas, of which the following is a specification.

The invention pertains generally to gas heatin and lighting systems and more particular y to means for supplying under pressure variable quantities of air and gas mixed in a predetermined proportion, the quantity of the mixture supplied being controlled by the amount consumed.

The general object of the invention is to produce a gas and air mixing apparatus of a practical character which is economical in operation and otherwise of high eiiiciency.

More specifically, one object of the invention is to provide improved means for vary- L. HILEs, a

\ `ing the quantity of the mixture produced at any time exactly in accordance with the quantity required for consumption. In prior devices of this general character the mixture produced by the apparatus over and above the demand therefor, is conducted back into the apparatus where it is again compressed. V'llhis obviously results ina waste of energy. Moreover, the recompression of the mixture results in the generation of heat which necessitates the provision of means such as a water jacket through which cooling water iscirculated to prevent the apparatus from becoming heated to such an extent as to be incapable of functioning properly. To avoid these difficulties, I provide a variable capacity compressor which is adapted to supply to the service main at any time a quantity of mixed air and gas suiicient to supply the demand only.

A further object of the invention is to provide means of improved construction and l arrangementl for maintaining substantially constant the proportion of a1r and gas constituting the mixture produced, it being a. well known fact that the resistance of air andgas vary disproportionately wit the enlargement or restriction of the inlet ports therefor, thus necessitating in the mixture of varying quantities of air and gas a disproportionate'varying of the sizes of their respective inlet ports.

When the gas to be mixed with air in the apparatus is supplied from a community station, the pressure thereof inthe main, as

details of construction.

ably mounted a rotor 16. Said casi will be readily apparent, iuctuates with the variation in the quantity of gas consumed. Another object of my invention is to provide improved means for stabilizi the owof gas through the inlet port Iig the apparatus. n

A further important object of the invention is to provide means for regulating the quality or richness of the mixture, by supplying at will a greater or less amount of the fuel gas to compensate for the variations in the B. t. u. value thereof.

Still another object of the invention is to provide :means operative when the apparatus is idle to prevent leakage of gas through the supply ports.

The objects of the invention thus generally stated, together with other and ancillary advantages, are attained by the construction and arrangement illustrated in the accompanying drawings forming part hereof, in which Figure 1 is a vertical section taken on line 1-1 of Fig. 3, of an apparatus embodying the features of my invention. Fig. 1i is a diagrammatic view showin a slightly modified arrangement. Fig. 2 1s a fragmentary central vertical sectional view through the apparatus. Fig. 3 is a vertical section taken on line 3-3 of Fig. 1. Fig. 4 is a transverse section taken on line 1 -4. of Fig. 1. Fig. 5 is a similar View taken on line 5-5 of Fig. 2. Fig.` 58L is a horizontal section taken in the plane of line 5*-5a of Fig. 1. Fig. 6 is a fragmentary section taken on line 6-6 of Fig. 2 and showing Fig. 7 is a fragmentary enlarged sectional view taken on line 7-7 of Fig. 1. Fig. 8 is a similar view taken on line 8--8 of Fig. 7. Fig. 9 is a fragmentary perspective view showing a detail of construction. Fig. 10 is a fragmentary sectional view taken on line 10 of Fi 2. Fi 11 is a front side elevation of a s ightly dii'erent form of apparatus. Fig. 12 is a transverse enlar ed sectional view taken on line 12-12 of F ig. 11. F ig. 13 is a fragmental vertical section on an enlarged scale taken on line 13-13 of Fig. 11.

The apparatus comprises generally a main casing 14 providing in its upper portion a cylindrical casing 15 within which is rotataan rotor form a compressor to which a mixture of air and gas is supplied by way of an elongated chamber 17 opening into one side ofthe casing 15. In the construction shown Mld in Figs. 1 to 4, this chamber 17 extends downwardly from the compressor and opens into a mixing chamber 18 of a casinor 19 on the forward side of the casin 14 and formin a part. thereof. Air an gas are supplied to this mixing chamber by means to be hereinafter described embodylng the means for varying the relative sizes of the gas and inlet apertures and the means for controlling the admission of gas at different pressures. 20 indicates a. ductopening from the casing 15 at the side opposite the chamber 17 and forming anoutlet for the mixture after havingl been compressed, and 21 is a pipe connecting said outlet with a chamber formed in the lower portion of the casing 14 by means of a diaphravm 22 which is operatively associated with the compressor to vary the capacity thereof asA more fully hereinafter set forth.4

The casing 14 comprises a lower or base portion 14a rectangular in form, the upper portion 14b of which is somewhat reduced 1n size to form a vertical guideway 23 1n which is mounted a plunger support 24 for a flexible member 25. The plunger sup ort 24, which is arranged to be supporte by the diaphragm 22 in a manner to be later set forth, is also rect-anfrular in form, having a sliding` but snug fit in said guideway 23, and the upper wall 26 of said support is curved to conform to the curvature of the adjacent stationary wall of the compressor casing. The flexible member 25 is secured to sald wall 26 of the plunger support, as by means of rivets 27, and its opposite ends are curved upwardly so as to slidably engage the peripheral wall of the casin 15 on op-posite sides thereof. In width sai member 25 is equal to that of the casing 15 and thus constitutes a movable wall or raceway for the rotor 16, The raceway is completed by the exposed portion 28 of the cylindrical wall of the casing 15. In ordcrto accom` modate the added thickness of the member 25, the portion 28a of the peripheralxwall, which underlies the member 25, is offset outwardly.

The rotor'16, -which may beof' anysuitable or preferred constru'cti'omis 'keyed' onto a shaft 29 mounted eccentrically ofthe cas'- ing 15, and carries a plurality of radially movableblades 30 held by centrifugal force,-

in the operation of the apparatus, in sliding engagement with the raceway of' the cornpressor. Herein the rotor is mounted in the uppermost portion of the casing, and it will be readily apparent, by reference to'Fig. 2, that` by movmg the plunger support 24 and with it the flexible member 25 toward and from the axis of the rotor, the effective eccentricity of the latter is decreased or increased and the capacity of the compressor thereby varied accordingly. In such movement of the plunger support 24 the opposite ends thereof slidably engage with the gerifpheral wall portion 28n at op osite si es o the compressor casing. It w1 be understood that any suitable means may be provided to rotate the shaft 29 to drive the compressor;

For the purpose of enabling the mixture of air and gas to enter the compressor from the chamber 17, the latter is made of greater width; than the raceway (Fig. 4); and to permit the discharge of the compressed mixture from the compressor the outlet duct 20 opening from the comp-resso-r casing is also made of greater width than the raceway (Fig. 6). Herein the chamber 17 and the duct 20 are shown as forming part of the casing 14, the upper portion of which may consist of a portlon 14c (Fig. 2) formed integrally with the portion 14", and separate sections 14d and 14e suit-ably secured together and to the portion 14c are respectively formed integral with the chamber 17 and duct 20.

In order that the blades 30 ofthe rotor may slide freely from the portion of their raceway formed by the cylindrical wall 28 of the casin onto the iiexible member 25, fingers 31 igs. 2, 9 and 10) are provided on the opposite upper ends of said member and have inturned ends 32 adapted to operate in narrow grooves 33 formed in the peripheral wall portion 28 of the casing. These fingers are made of a length slightly greater than the extent of vertical movement of the member 25 so that when said member is in its lowermost position (see Fig. 10) or higher, the blades 30 of the rotor while traveling between the portion 28 of the ripheral wall of the casing and the flexile member 25, and vice versa will be supported by the fingers against outward movement into the offset portion 288L of the cylindrical wall of the casing. In Fig. 10 t e upper limit of the offset or enlarged portion 28EL of the peripheral wall of the casing is shown at `34. In order that' the air and gas which may find its .way beneath the yflexible member 25 may freely escape when the member moves toward its seat upon the peripheral wall of the casing, the grooves 33 for the fingers 31 may be continue-d downwardly substantially to the top of the plurnger support, as shown at 33a' (Figs. 2 and 4).

The means'for con-trolling the position of the plunger 'support24 and thereby of the flexible member or raceway 25, will now be described: Referring to Figs. 1, 2, 3 and 5- theplunger support 24 is mounted on the upper end of a rod 35, the lower end of which is fixed centrally of the diaphragm 22. The edges of said diaphragm are here in shown as clam of the base portion 14 of the casing 14 and the diaphragm thus forms a chamber in the lower portion of the casing which is at all d between two sections irs.

times in communication with the outlet duct ofthe compressor through the pipe 21.

Said duct constitutes the service main of'the apparatus. It will be seen that as theprese sure in the service main rises and falls 1n accordance with the consumption of the mixture, the dia hragm 22 and thereby the rod and flexib e raceway 25 are caused to rise and fall.

To facilitate the diaphragm in thus imparting vertical movement to the flexible member 25, means are preferably provided for partially counterbalancing the vertically movable parts. Any suitable means may be employed for this urpose. Herein I have shown a counterwelght 36 slidably mounted on the rod 35 so as to be guided thereby and having laterally extending arms 37. At the free ends of these arms are'mounted a pair of levers 38 and 39 pivotally mounted on brackets 40 and 41 which a-re fixed on opposite sides of the casing; and said levers each have a slotted pivotal connection with a collar 42 fixed on the rod 35. The proportion and arrangement of the parts is such as to resist an upward movement of the diaphragmI except when the pressure on its under slde f exceeds a predetermined amount. This ensures the maintenance of the required pressure in the service main. In order that the eect of the counterweight may be varied at will, the ivot of one of said levers is in the form o a rock-shaft which carries an.

arm 43 having in turn a weicht 44 adjustable 'gthereon. It will be seen that by adjusting Lthe position of the weight 44 the counteracting effect of the counterweight 36 ma be readily varied. To permit of such adjustment the casing is provided with an opening 45 (Fig. 3) whlch may have a suitable closure 46.

Referring now to the means for regulating the admission' of air and gas to the apparatus: The casing 19 in which is provided the mixing chamber 18 (Fig. 3) is also provided with an air inlet chamber 47 and a gas inlet chamber 48 (Figs. 3 and 5a).

These chambers are formedby dividing the 19 belovvthe chamber portion of the casin 18 centrally thereof y means of a partition 19a, (Fig. 5). To permit the passageof air and gas from these chambers 47 and 48 to the mixin chamber 18, ports 49 and 50, 49a and 5()a (gl 1 igs. 1 and 3) are provided in the inner Wall of said casing 19. Said ports 49 and 50 open respectively into by-passes 51 and 51El formed in a pendent portion 52 (Figs. 3 and 5"*) of the plunger support 24. The ports are herein made rectangular vin form, and the ports 49 and 50 open/ respectively from the air'and gas chambers 47 and 48 into said by-passes 51 and 51, and the ports49aand50open fromtheirrespectivebypasses into the mixing chamber l18. ln the outer Wallof the casing 19 apertures 53 and 54 are provided opening respectively into the chambers 47 and 48. Tt will be seen that From the mixing chamber thethat as the plunger rises with the decrease in the consumption of the mixture, the admlssion of air and gas is restricted. 'To this end said portion 52 has a dependent plate 55 adapted to decrease the size of the apertures formed by the ports 49 and 50 as the rate of consumption decreases and the plunger support 24 rises.

It will be seen that with a decrease in the consumption of the mixture, not only is the capacity of the compressor decreased, butv the volume of the mixture admitted thereto is also diminished. (lwing, however, to the fact that the resistances of -air and gas do not vary in the same roportion as the sizes of their respective in etsare varied by the plate 55 in the movement of the plunger support 24, I preferably provide means for disproportionately varylng the v sizes of said inlets. This means comprises a plate or slide 56 (Figs. 1 and 3) mounted wlthin the casing 19 and slidable throu h the partitionl 19a therein. A portion of t e slide extends into each of the chambers 47 and 48 and slidably engages the inner Wall of the casing in which are located the rts 49 and 50, the slide being of sufiicient ength to partially cover both of these ports as shown in Fig. 1 (dotted lines). It will be se'enthat when the slide is moved in either direction it will serve to increase the size of the aperture of one of said ports and correspondingly de` crease the size of the apertureof the other one of said' ports, and in order that this may be accomplished as the rate of consumption vvaries,l have provided means by which the i up and down movements of the plunger support and itsl depending ortion impart a lateral movement to the s ide. To this end the lower edge of the slide is rovided with rack teeth 57 Fig. 1) adapted) a pinion 58 W ich is fixed against rotation but slidable on a shaft 59.' This Shaft 59 extends through a depending ear 60 of the casing 19 and is operatively connected to the pendent rtion 52 of the plunger support so as to bl); rotated thereby as the support rises and falls.

lj'referably, the means for accomplishing this result is so arranged that the slide may to mesh with' ing engagement.

be moved manually for the'prpose of-adjustment. Thus, referring to Fi 7 and 8, the shaft 59 lhas mounted on its mner end av loose clutch member 61 and also has a fixedv clutch member 62. A spring 63 on the shaft bearing between the portion 60 of the casing and a collar 64 fixed on the shaft, serves to normally hold the clutch members in hold- Said clutch members are mounted within an aperture 65 (Figs. 7 and 8) formed in the lower portion 14 of the casing, and the loose clutch member 61 carries an arm 66 passin through a staple 67 in the plate 55. It w1 l be seen that 1n the.

normal position of the parts the movement imparted to the plunger support 24 ,by the pressure in the diaphragm'chamber will also be imparted to the slide 56, and the parts are so arranged that as the plunger support rises with the decrease in consumption of the mixture, the air inlet is increased and thegas inlet restricted; and when the consumption increases the reverse action taires place. The extent of such movement to be imparted f to the slide may of course be readily controlled as desired byproperly roportioning the connection between it and e vertically movable plate 55.

In order to facilitate the adjustment of the slide the rod or shaft 59 is provided on itshfree end with a hand wheel 68, and the rod may be provided with a pointer 69 movable relative to a dial 70 on the casing 19. When it is desired to adjust the slide relative t'o the arm 66 and plate 55, it is only necessary to pull the rod outwardly until the clutch member 62 is disengaged from the clutch member 61, the latter being held against outward movement by the arm 66 which is held to the plate 55 by the staple 67. In this movement of the rod the pinion 58 thereon remains in mesh vwith the rack teeth 57 on the slide so that by rotating the rod the slide can be moved as desired 1nde pendently of the plunger support 24.

When the gas to be supplied' to the apparatus is taken from a city or other community supply main, where the pressure varies almost continually, it becomes necessary to provide means for preventing'such variation in pressure in the supply main from affecting the volume of gas admitted to the apparatus. Herein, to accomplish this result, I provide a gas inlet port, the area of which is adapted to be varied with the rise and fall of the pressure in the supply main. Said port is Jformed by the inner end of apipe line 7l leading to the opening 54 of the chamber 18. To control said pprt I rovide a valve `late or member 72 slidable 1n a casing 7 3`-( ig.v 4) which maybe formed integral with--an annular rin 74 (Fig. 4) forming part of the pipe line 1. A bellows diaphragm 75, is adapted to receive pressure from the 'supply main to operate said valve 1,4se,o11

plate 72, and to this end a pipe. 76 leadin' from the pipe line71 opens into one end ,o the bellows diaphra and the other end of the latter has a sli ing connection through the medi-um of a link 7" with a lever 78. Said lever is pivoted to a bracket 7 8 at its upper end, and at its lower end slidably engages the free end of a rod 79 carried b the valve member 72 and' extendin throng one end of the casing 73. It wil be seen that as the preure in the supply main varies the pressure upon the bellows diaphragm also varies, an increase of pressure in the main serving to effect a closing movement of the valve member and a decrease of pressure serving to effect an openmg movement of said member. By thus varying the size ofthe inlet port controlled by the valve member 72 in proportion to the pressure in the supply main, the volume of gas admitted through the inlet port is electively controlled so that the fluctuating pressure in the gas main is prevented from affecting the supply of gas to the apparatus. In order that the osition of the valve member 72 may be a justed to permit the passage of the required volume of gas at different pressures in the main, the effective length of the lever 78 may be made variable. Herein the supporting bracket 78a to which the lever is pivoted, is provided with a slot 80 (Fig. 1) to enable the pivotal point of the lever to be varied relative to the point of its connection with the link 77. By this means the parts may be readily adjusted as desired', such for example, that when the pressure in the main falls to one inch, water column, the passage-waythrough the pipe line is wholly unrestricted by the valve member, and as the ressure in the gas supply main increases, t e valve member gradually closes said passage-way.

Summarizing the operation of the apparatus as above set forth: The shaft 29 of the compressor being driven from a suitable source of power (not shown) to operate the compressor, suction in the elongated chamiber.. 17 is created. Thereupon, air entering the inlet chamber 47 through the opening 53, at atmospheric pressure, and gas entering the inlet chamber 48 through its inlet port, are drawn through the by-passes 51 and 51a into the mixing chamber 18. From said chamber the mixture passes into the chamber 17. The admission of gas through the inlet port is controlled by the operation of the bellows diaphragm 75 actuated by the pressure of the gas in said supply main to move the valve member 72, which is interposed in the gas supply port or passageway. From the compressor the air and gas,

thoroughly mixed and compressed, pass into the outlet duct 20 or service main. As the amount of mixture supplied to the service main exceeds the demand therefor,

' lthe increasing pressure in the service main ,50 and to restrict t e aperture .port 4:9.V

is transmitted to the diaphra 22 through the pipe 21, and the diap ragm acting through the rod and the plunger support 24 moves the iexible raceway 25 upwardly toward the axis of the compressor rotor,

thereby decreasing the capacity of the coinpressor and hence the amount of mixture supplied to the service main. Such upward' .movement of the plunger support 24 also causes -tlie pendent portion 52 and valve plate 55. to rise to graduallyclose the inlet ports 49 and 50, lthus decreasingthe volume 11 and 13, ll provide butterfiy valves 85 and 85a in the chambers 82 and 83, -both fixed upon a rod 86 passing through both chambers as well as the partition 81.'l 0n the vas above set forth. Thus referring to Figs. 7o

free end .of said rod is a crank arm 87 which te is connected by a. link 88 to'a crank arm 89 carried by the lower-end of a rock shaft 89a (Fig. 11). rlhe latter is pivotally mounted of air and gas supplied to the mixing chamn brackets 89b carriedby the compressor casing adjacent the shaft thereof and on its ber. At the same time the upward movement of the plate 55 acting through Athe arm 66,'shaft 59 and pinion 58, causes the slide 56 to increase the a erture 'throu h the port rough the Such disproportionate variation in the sizes of the air and gas ports is e'ected in order to compensate for the disproportionate variationin resistance of air and gas as the sizes of their respective inlet let 4vide apertures vary. When the surplus mixture has been consumed so that the pressure in the service main varies, the valve plate 55, slide 56 and movable raceway 25 operate reversely to produce an increased supply of mixture. i

lf desired, the control of the admission of air and gas into the apparatus by means such as the slide valve 56 (Fig. l) which is directly associated with the plunger support 24 may be omitted. Thus in the form of apparatus shown in Figs. 11 15o-13, a chamber 17 terminating below the comressor casing constitutes the mixing cham- Eer for the air and gas communicating with the ressure inlet. To this end it is prowith a central partition 81 in its lower end (Fig. 13) .forming an air inlet chamber 82 anda gas inlet chamber 83. The former chamber is open at its lower end to permit the entrance of air, while the latter chamber is closed at its lower end and in one side .has'an opening 84 into which a gas-inlet pipey 84a enters. Suitable means may be rovided for controlling the area of .the gas inlet port formed by the pipe 85, in

accordance with the variation in pressure in the supply main, as, for example, that shown in Figs. 1, 3 and 4. It will be understood that in this ,construction the variable capacity of the compressor is depended upon entirely to vary the quantity of mixture produced-by the apparatus, this being accomplished in the manner above set forth in connection with the first form of the apparatus described.

In order to prevent leakage of gas from the apparatus when it is idle, either by wav ofthe gas inlet or from the compressor, preferably provide means' for automatically closing both the air and gas inlet chamupper end carries an arm-y 89c arranged to be swung by a suitable governor mounted on y an extended endV 29a of said shaft. Herein, said governor comprises aixed collar 90 on the shaft and a slidingcollar 91 E@ connected by a pair of jointed links 92 carrying weights 93 at their joints and connected by a spring 94. The sliding collar 91 has an annular groove 95 therein for engaging a yoke 96 on the crank arm 89. It 9U crank arm 87 rotate-the rod 86 carrying the 95 valves 85 and 85a. The parts are so proportioned and arranged that as soon as the apparatus is set in operation both 'of said valves will be swun into open position, the restriction of both inlets being removed simultaneously so as to permit of the admission of the air and gas in the proper proportion whi-le the valves are being opened.

It will beseen that I have produced an air and gas mixing apparatus of an advantageous and eflicient character. Various means-,of practical construction are provided to meet the peculiar conditions naturally arising yin actual practice. The means for disproportionately varying the sizes of the air and gas ports is very simple in construction and arrangement, embodying a single positively operated valve member imparting the attribute of certainty to the operation. Moreover, the difliculty arising from the iiuctuation in pressure of the gas in the service main is eectively overcome. At the same time thev volume of mixture supplied to the service main is quickly and accurately regulated in accordance with the demand without necessarily burdening the compressor, effecting a saving in motive power and also eliminating useless wear and tear upon the parts.

It will also be observed that by varying the capacity ``f the compressor the volume of air and gas supplied to the service main is limited to that actually required for consumption at any given time. It the demandl increases, producing aff/fall in pressure in the service main below that detox mined by the weights, the compressor promptly responds to increasethe supply; and 1f the demand` decreases, the r1se 1n pressure in the service main causes a corres onding decrease in the volume supplied.

one of the mixture therefore is returned by a by-pass to the compressor inlet, as in prior apparatus, and the result isthat the proportion of air and gas constltutmg the mixture is maintained substantially constant notwithstanding the rise and fall of the pressure in the service main. This follows from the fact that the return of a variable quantity of the mixture from the compressor outlet to the inlet is. a disturbing factor in the system in that 1t produces at the compressor inlet a suction of varying intensity depending'l upon the quant1t y of the mixture returned. The result 1s that the proportion of air to gas entermg the -compressor, as predetermined by the relativesizes of the inlet openings, is destroyed since the air and gas, being of different specific gravities, respond dlflerently to a' suction of varying intensity. In the present instance, the intensity of the suction at the compressor inlet is maintained substantially constant. Hence the proper proportion of air and gas in the mixture, for combustion purposes, with a resulting high efficiency of the system is assured.

The variable capacity compressor is of very simple construction and operation,

/and it will be seen that its use is not limited to air and gasV mixing apparatus, but may be employed in other connections which will readily suggest themselves to those skilled in the arts. I also desire to` have it understood that while the'invention is herein illustrated and described with considerablel Iparticularity, it is not to be limited, in the interpretation of the ap` pended claims, except as may be necessitated by the prior state of the art. v

I desire particularly to point out that the apparatus is not one limited to the mixing of air with a single kind of gas or to the mixin of air with gas from a single source,

for o viously the construction may readily varied without departing from the spirit and scope of my invention to enable the mixing of several gases, it being only necessary to provide additional inlet ports and controlling means therefor of the character set forth. Thus, in Fig. 1 I have shown diagrammatically an arrangement in which a gas inlet port 97 is provided-in addition to air and gas inlet ports 98 and 99. This port` 97 may be controlled by a slide 100 which may be operated in any suitable manner but independently of the slide 56a which controls the ports 98 and 99. It will be apparent that by means of such additional inlet port, an enriching gas ma be introduced into the .apparatus for t e purpose of increasing the heating or B. t. u. value of the mixture.

. I claim as my invention l. An apparatus of the character .described comprising, in combination, a compressor of the positive blower type having an inlet and an outlet, a mixin communicating with said inlet, air and gas inlet chambers communicating with said mixing chamber, a closed chamber having a diaphragm, means establishing communication between said compressor outlet and said diaphragm chamber, 'and means actuated in the movement of said vdiaphragm to vary the capacitykof said compressor whereby to limit the volume of mixture passing therethrough to that required forconsumption at any given time.

2. An apparatus of the character described comprising, in-combination, a compressor having an inlet and an outlet a mixing chamber communicating with sai compressor, air and gas inlet chambers comchamber n closed chamber having a diaphragm, said` compressor embodying a casing having a rotor mounted eccentrically thereof and a movable peripheral wall, and means actuated in the movement of said diaphragm to move said wall toward and from the axis of the rotor to vary the capacity lof the compressor so as to limit the volume of mi;- ture discharged to that actually required for consumption.

3. An apparatus of the character de scribed comprising, in combination, a main casing providing a compressor in its upper portion provided with a movable Wall, an auxiliary casing at oneI side of the main casing and provided with an air-inlet chamber and a gas inlet chamber each having an inlet and an outlet, and a mixing chamber having an inlet, an outlet communicating with the compressor inlet, a closed chamber having a diaphragm, means establishing communication between said closed chamber and said compressor outlet and means operable in the movements of said diaphragm to actuate said movable wall to vary the volume of the mixture produced and including means providing valved communication between said inlet chambers and said mixing insonni lisliing communication between said closed chamber Fand said compressor outlet, and

means actuated in the movement of said diaphragm to-vary the capacitycf said compressor and including'means establishing communication between the outlet ports of said inlet chambers and the inlet of said mixing chamber.

5. An apparatus oit the character described, having, in -combinatoin, acasing having a compressor therein providedv with an inlet and an outlet, -a mixing chamber communicating with said compressor inlet. said casing having an air inlet port and a gas inlet port, means establishing communication between said inlet ports and said mixing chamber, a closed chamber having a diaphragm and communicating with the com ressor outlet and means comprising a sing e valve member and a part actuated in the movement of said diaphragm and having a gearing connection with said valve member whereby to disproportionately vary the relative sizes of said ports as the pressure in the compressor outlet rises and falls.

6. An apparatus of the character described comprising, in combination, a casng havin a compressor therein provided ith an inlet and an outlet, a mixing chamber communicating with lsaid compressor inlet, said casing having anl air inlet port and a gas inlet port, a closed chamber having a diaphragm and communicating with the compressor outlet means actuated in the movement of sai diaphragmV to establish valve-controlled communication between said ports and said mixing chamber, and separate valve means also actuated in the movement of said diaphragm to vary disproportionately the relative sizes of said ports.

7. An apparatus of the character described comprising, in combination, a casin` having an outlet duct, a compressor adapte to discharge intol said outlet duct a mixing chamber communicating with said compressor, said casing having an air inlet port and a gas inlet port, aslide valve adapted to be actuated by the pressure of the gas at the source of supply for varying the area of the gas inlet port as the pressure in the supply main fluctuates, and means establishing communication between said inlet ports and said mixing chamber operable directly by the pressure of the mixture at the compressor outlet to vary*I the volumes of air and gas passing therethrough.

8. An apparatus of the character described having, in combination, a casing having an outlet duct, a compressor in the casing communicating with said duct, a mixing chamber communicatin with said compressor, an air'inlet cham er and a gas inlet chamber normally communicating'with said operation, and means operatively associated with the compressor whereby to cut ed communicati'on between the inlet chamber and `tgilie mixing chamber when the apparatus is 'i e. f

9.. An apparatus of the character described having, in combination, a casing having an outlet duct, a compressor in the casing discharging into said duct, a mixing'chamber cpmniunicatm with said compressor, an air inlet cham rand a gas inlet chamber arranged to communicate with said mixing \chamber, a valve for each of said chambers, and a governor operatively associated with the compressor and said valves whereby when the compressor is in operation communication between the inlet chambers and said mixing chamber is open, and when the compressor is idle such communication is closed.

.10. An apparatus of the character described comprising, in combination, a. cas'- ing` having a mixing chamber, a gas inlet port and an air inlet port each communicating with said mixing chamber, said casing having a cylindrical portion rcommunicating with said mixing chamber and having an outlet duct, arotor mounted eccentrically within lsaid cylindrical portion of the casing and having radially movable blades, al memberconstituting a movable peripheral wall providing a raceway vfor the ,blades of the rotor, and means operable with the rise and fall of pressure in said outlet duct to vary the position of saidinember relative to said rotor whereby to limit the volume of the mixture passin through the. compressor to that actual y required for consumption.

11. An apparatus of the character described comprising, in combination, a casing having a mixing chamber, a gas inlet,port and an air inlet port each communicating with said mixing chamber, said casing having a cylindrical portion communicating with said mixing chamber and having an outlet duct, a rotor mounted 'eccentrically Y within said cylindrical ortion of the casing havingA radially movab e blades, a member constituting a, movable wall for the compressor thus formed adapted to be slidably engaged by said rotor blades, a closed chamber within said casing communicating with said duct and having a diaphragm, and means actuated in the movement of said diaphragm to vary the position of said member relative to said rotor whereby to equalize thevolume of air andgas drawn from the inlet ports into the com ressor and the volume of the mixture discharged by the compressor.

12. An apparatus of the character described comprising, in combination, a casing having a mixing chamber, a gas inlet port lll mixing chamber when the apparatus is in and an air inlet port each communicating 1w with said mixing chamber, said casing havin a cylindrical with said mixing c amber and having an outlet duct, a rotor mounted eccentrlcally within said cylindrical portion of the casing, a member constituting a movable wall for the `'compressor thus formed, a closed chamber within said casing communicating with said duct and having a diaphragm, and means actuated in the movement of said diaphragm to limit the volume of air and gas passing through the compressor'to that required for consumption by varying the position of said member relative to said rotor, said means comprising a supporting member for said member slida'ble vertically in the casing, a counterweight operatively connected with said supporting member', and adjustable means for varying'the counterbalancing eiect of said counterweight.

13. In an apparatus for mixing air and gas, a compressor having an inlet and an outlet, a mixing chamber, means for admitting quantities of air and gas in a predeter-mined pro ortion to said chamber, and means operab e by the pressure at the compressor outlet to equalize at all times the volume of the mixture entering, passing through and leaving the compressor.

14. iAn apparatus of the character described comprising, in combination, a 'comressorprovided with an inlet and .an outlet, means for conducting quantities of air and gas to the compressor inlet, a closed chamber having a diaphragm, means establishing communication between saidclosed chamber and said compressor outlet, `and means actuated in the movement of said diaphragm to vary the capacity of the compressor in accordance with the volume of the 'mixture consumed at anygiven time.

15. An apparatus. of the character described comprising, in combination, a casing having an air inlet port and a gas inlet port, a mixing chamber, means establishing communication between said ports and said mixing chamber, a compressor having an inlet andan outlet, means establishing communication between said mixing chamber and the inlet of the compressor, a closed chamber having a diaphragm, a pipe connecting said compressor outlet with said closed chamber, a member guided for vertical movement in said casing and operatively associated withsaid diaphragm to be moved up and down in the movements of the diaphragm, and a slide for governing said inlet ports operatively associated with said vertically movable member so that in the movements of the latter the slide restricts one of said inlet ports and enlarges the aperture of the other inlet ort. p 16. In an apparatus of the character def scribed comprising a casing having a compressor therein and having a gas inlet port ortion communicating and an air inlet port, and means for disproportionately varying the sizes of the apertures through sald ports as thequantity of air and gas drawn t rough 'said ports varies, said means comprising a vertically movable member in said casing, a slide for governing said inlet ports, a rock shaft having a aring connection with said slide, an an arm operatively associa with said vertically movable member so that in vertical movements of the latter a lateral movement is imparted to the slide.

17. In an apparatus of the character described comprising a casing having a compressor therein and havinga gas inlet port and an air inlet port, and means for disproportionately varying the sizes of the apertures through said ports as the quantity of air and gas drawn through said orts varies, said means comprising a vertica ly movable member in said casing, a slide for governing said inlet ports, a rock shaft having a gearing connection with said slide, and an arm operatively associated with said vertically movable member so that in vertical movements of the latter a lateral movement is imparted to the slide, said rock shaft havin a disengageable connection with said mem r to permit of the adjustment of the slide independently of the member.

18. An apparatus of the character described, comprising, in combination, a casing having an air inlet port and a gas inlet port, a mixing chamber, means establishing communicatlon between said ports and said mixing chamber, a compressor communicating with said mixing chamber, and including a member movable to vary the capacity thereof, and means operatively associated with said member for disproportionately varying the relative Sizes of said inlet ports as the volumes of air and gas drawn into said mixingV chamber by said compressor vary. v

19. An apparatus for mixing air and gas 110 comprising, in combination, a compressor having an inletv and an outlet, a mixing chamber communicating with the compressor inlet and also with an air inlet port and two gas inlet ports, valve means operable by the 115 pressure of the mixture at t e compressor outlet to control the air inlet port and one of said gas inlet ports, and means independ. ent of the last mentioned means for controllin the other one of said as inlet ports. 120

20. n apparatus for pro ucing a combustible gaseous mixture comprising, in combination, a compressor having an inlet and an outlet, a mixing chamber communicating with the compressor inlet and also 12,5 with an air inletv port and two gas inlet ports, means controlled directly by alterations in the ressure of said mixture to control onev o said as inlet ports, and means independent o the last mentioned 180 sie controllingy means for controlling the other inlet ort.

2l. he method of producing a combustible mixture of gas and air which consists in supplying to a compressor quantities of gas and air through a pair of inlet ports in predetermined proportions, oontrolling such supply automatically 1n accrdance with the pressure of the mixutre at the compressor outlet, and supplying to the compressor at will a variable quantity of gas to compensate for any variation in the B. t. u. value of the gas forming part of the mixture.

22. The method of producing a gaseous mixture for combustion which consists in supplying to a compressor in the desired proportions. the which constitute the mixture, and limitin the volume of the mixture passing throug the compressor at any time to that actually required for consumption.

23. The method of producing a combustible gaseous mixture which consists in supplying to a compressor in the desired proportions the ases constituting the mixture, and control ing the volume of the mixture discharged Iby the compressor into the service main by varying the volumetric capacity of the compreor to limit the volume passing through the compressor at any given time to that actually required for consumption at that time.

24. In a system for supplying a variable quantity of air and gas for combustion, the combination of a compressor having an inlet for air and gas, means for admitting air and as to said inlet in a predetermined proportion, a service main into which the compressor is adapted to discharge the mixture of air and gas, and means controlled by the pressure in the service main` for limiting the volume of air and gas discharged by the compressor into the service main in accord ance with the volume of the mixture actually required for consumption.

25. In an apparatus for supplying a varable quantity of air and gas for combustion, a compressor having an inlet and an outlet, means for admitting to the inlet a supply of air and gas in a predetermined proportion, and means controlled by the pressure at the compressor outlet for varying the Volumetric capacity of the compressor whereby to limit the volume of mixture discharged from the compressor to that required for consumption.

.26;'In a gaseous fuel supply system, the combination of a compressor having a inlet and an outlet, a service main communicating with vthe' outlet, means for supplying air and gasto the compressor inlet, means for controlling the iiow of air and gas to said inlet in a 4predetermined proportion, and means controlled by the pressure in the service main for limiting the volume of airstantially to the volume required for consumption at any given time, the means for controlling the volume of air and gas iiowing to the compressor being also controlled by the varying pressure in the service main.

In a gaseous fuel supply system, the combination of a compressor having an inlet and an outlet and comprising an annular caslng having a peripheral Wall, a rotor mounted in said casing and having a plurality of radially movable blades for slidably engaging said wall, means for admitting air and gas to the compressor inlet in a predetermined proportion, and means controlled by the compressor at the compressor -outlet for effecting relative movement between said peripheral wall and said rotor whereby to limit the volume of the mixture entering the compressor to that required for consumption at any given time.

28. In a gaseous fuel supply system, the combination of a positive type blower or compressor comprising an annular casing having a movable peripheral wall portion and a rotor mounted in said casing and having a plurality of radially movable blades, means controlled by the compressor at the compressor outlet for admitting a plurality of gases to the compressor in a predetermined proportion to constitute the aseous mixture, and means also controlled y the pressure at the compressor outlet for moving said wall portion to vary the volumetric capacity of the compressor whereby to limit the volume of mixture discharged from the compressor at any given time to that actually required for consumption at that time.

29. In a gaseous fuel supply system, the combination with a service line, of a compressor comprising an annular casing having an inlet and an outlet, said outlet communicating with the service line, means for admitting quantities of air and gas in a predetermined proportion to said inlet, a rotor mounted in said casing so as to operatively engage therewith to effect the positive movement of the gaseous fluid therethrough, and means controlled by the pressure at the outlet of the compressor operable to equalize at all times the volume entering, passing through and discharged into the service line.

30. In a gaseous fuel supply system, the combination with a service line, of a compressor for delivering a variable volume to said service line as determined by the demand, said compressor comprising an annular casing, a movable inner peripheral Wall, and a rotor adapted to eiiect the positive movement of iiuid through the casing; means for admitting the gases to constitute the mixture in a predetermined proportion to the compressor inlet, and means operable automatically to move said wall with respect to the casing whereby to equalize atall times the volume entering and passing through the compressor with that discharged into the service line.

5 31. The combination with a service line,

of a compressor comprisin an annular cas- 'ing, a rotor mounted in sai casing and having a plurality of radially movable blades, and means controlled by thepressure in the 10 service line whereby to limit the volume of fluid passing through the compressor to that required for consumption at any given time, said means including a peripheral Wall movable toward and away from therotor to vary the capacity of the compressor and capable of bending or flexing in such movement as its radius decreases or increases.

In testimony whereof, I have hereunto set my hand.

THERON L. HILES. 

